This amazing map shows just how little of our galaxy we’ve explored so far

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Using NASA’s Spitzer Space Telescope and the Optical Gravitational Lensing Experiment (OLGE), astronomers have discovered a planet that’s roughly 13,000 light-years from Earth — one of the furthest ever such exoplanets ever discovered. The official name for it is OGLE-2014-BLG-0124L, which like most of these, rolls right off the tongue. Not much is known about this planet other than the fact that it’s a gas giant.

Coinciding with the discovery, NASA/JPL has released an artist’s rendering of a map showing exactly where we’ve found exoplanets to date. It’s amazing: We’ve barely scratched the surface of our own galaxy, which is 100,000 light-years across, even after finding more than 1,800 exoplanets so far (and 4,600 other possible suspects). Each time we get a little push or bump in technology or search methods, we’re able to push our search that much further out.

There are many methods scientists use to find exoplanets, and nearly all of them are indirect in some way (i.e. not visibly observed). Let’s review three of the most common ones.

The ‘transit’ method: Scientists discovered the first exoplanets using ground telescopes and what’s called pulsar timing and radial velocity, but a more common method used since the turn of the century is the ‘transit’ method. It’s pretty simple; when a planet crosses in front of a star, that star dims ever so slightly. So going by the distance to that star, and the relative sizes of the star and planet, you can confirm a planet is orbiting a star by the regular, very small dips in brightness.

In the map below (click it for a larger version), most of the planets found this way are in the orange-pink circle around our Solar System. More recently, scientists are sifting through data from NASA’s Kepler space telescope, using the transit method and others to find possible candidates. Exoplanets found with Kepler are shown with the orange-pink “cone” that extends outward, representing the space telescope’s field of view.

Gravitational microlensing: Astronomers are also working with a technique called microlensing (illustrated below) to reach these further-out exoplanets, like the one that’s 13,000 light-years away. The gravitational field of the star acts like a lens that magnifies the light from a distant background star. If there’s a planet present, that will affect the results in an extremely tiny, but still detectable way. Exoplanets found with microlensing are in yellow. The furthest-out one we found so far is about 25,000 light years away, and sits just near the center of our galaxy.

Direct observation and imaging: This one is extremely tough with our current level of technology, and only relatively recently (2008) was it confirmed that the first exoplanet was found in this manner. In these cases, usually the planet is very young, emits infrared light, and is far enough from the glare of the star that you can pick it out.

Where did the pic of the milky way come from? is this just a spiral galaxy that we have co-opted for illustration purposes or what?

bmwman91

I was wondering the same thing. Surely we don’t know what the Milky Way looks like in its entirety?

Mirimon

Exactly… to us looking across our galaxy would be like looking at any shape in flat world….we likely would not know for sure until we send something away from the plane far enough to kook back, and send telemetry…by then we will have died or colonized 3 solar systems.

Ilya

We have quite an accurate understanding of what the Milky Way looks like – two major arms, and small offshoots… if you’ve seen a thousand oranges and are looking at one from inside of one (helpful if it is a bit see-through like the Milky Way is! :p ), you can get a pretty good picture of where the bumps and pips are. Gaia is making a map of 1% of the Milky Way’s stars atm though, again – will be more of a map of the closes region of the galaxy though!

Jeff Vahrenkamp

yeah, that’s just “an artists idea of what our galaxy may look like”. We have a little bit of an idea of what our side (The stuff that’s on the same side of the galactic core as us) looks like. We know our galaxy is a disk shape (this is a no brainer for anyone whose seen a long exposure of the milkyway in the night sky), we know it has arms (this was figured out by measuring the distance to clumps of stars in the disk of our galaxy, which are grouped at certain distances), and we know we have a nice galactic core. But beyond that it’s still up for debate as to what the shape of our galaxy is, we could have a sweet bar in the middle, or lots of arms, or who knows what…

Jeff did a nice job of answering, but I’ll add just one thing: It still boggles the mind to think we didn’t know what our own planet looked like, in full, until 1972. Wouldn’t it be amazing to see the “Blue Marble” photo of our own galaxy occurs? (i.e. the “white spiral,” or whatever they end up calling it) Unfortunately, I can’t imagine this actually happening, because it takes light 100,000 years to travel the length of the Milky Way alone. But it’s still fun to think about.

> ” I can’t imagine this actually happening, because it takes light 100,000 years to travel the length of the Milky Way alone. But it’s still fun to think about.”

The discovered Planet is 13K LYs away. Either the Civilization in that area died long ago or they are over 13,000 years ahead of us in technology (and may arrive here tomorrow).

Yes, if we could travel the speed of light and lived 1000 times longer, we could travel from (what we think is) one end of the Galaxy to the other (in a lifetime).

I think we will need “Quantum Communication” (or a “Quantum Vision Technique”, for want of a better explanation) to both “see” and communicate with these distant Planets; else viewing them is like looking at ancient history (not as interesting to some as what is currently occurring – like their arrival – oooh ).

First we will master “detection of Gyrocopters in restricted airspace”, then on to the big stuff ! Way better to live THIS Century than the last one (IMO).

PS: Why they named it “OLGE” and not “OGLE” is another mystery. ;)

VirtualMark

Actually if we travelled at the speed of light, to us it would appear as if we arrived there instantly. To an outside observer it would take thousands of years. Relativity is weird like that.

Matt Menezes

Yeah, I always found it crazy that a photon doesn’t experience causal time and hence doesn’t degrade because it’s traveling at the speed of light.

VirtualMark

Yeah it’s amazing, especially when you consider that some of them have been travelling for billions of years.

Matt Menezes

Incidentally, the fact that neutrinos oscillate shows they experience causality and thus can’t travel exactly at the speed of light. This also meant they could (and do) have a small mass.

VirtualMark

They had a guy fly up there and take it.

Douglas Ahlquist

we got it from alien visitors, of course.

Mirimon

Meh, I got further in Elite: Dangerous

Tom

So did the Alliance with their recent community exploration goal. I didn’t take part, was busy trying to find some stupid C3 gimbaled pulse lasers. Those guns are like unicorn s**t.

VirtualMark

We’ve barely scratched the surface of the Milky Way, but at the same time we’ve not even sent humans as far as Mars yet. These exoplanets are so far away that it defies belief, yet they’re right on our doorstep as far as the Milky Way is concerned.

Ken3580

I saw an article today that called the Kepler telescope “Son of Hubble.” Gee, if they had named the Hubble telescope after Hillary, they could have called Kepler, “Son of a Bltch.”

Astronomers, don’t know. The story keeps and always will be changing. There is no objective reality. We have created the Universe from our minds, and minds keep changing. Read a book entitled, SAVING THE APPEARANCES, by Owen Barfield.

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